This invention relates to a head apparatus, a hard disk apparatus and a recording and playback apparatus, and more particularly to a head apparatus which includes a recording head for recording information onto a recording medium and a playback head for playing back the recorded information, and a hard disk apparatus and a recording and playback apparatus wherein the head apparatus is used to record and play back information onto and from a hard disk.
A general configuration of a recording and playback apparatus for recording and playing back information onto and from a recording medium such as, for example, a hard disk drive (HDD) apparatus which uses a hard disk as a recording medium is shown in FIG. 7. A hard disk drive apparatus uses a magneto-resistive (MR) head (hereinafter referred to as MR head) as a playback head and uses an inductive head as a recording head. For example, a thin film (TF) head (hereinafter referred to as TF head) is known as the inductive head.
Referring to FIG. 7, a signal processing IC (read/write (R/W) IC) 201 having the functions of a playback amplifier and a recording driver is mounted on a flexible board 202, and a head section 204 for recording/playing back onto/from a recording medium such as, for example, a hard disk 203 is carried on a suspension 206 mounted at a free end of a head arm 205. The head section 204 is connected to the signal processing IC 201 by signal lines which extend through the suspension 206, the head arm 205, a head wiring line junction section 207 and the flexible board 202.
FIG. 8 shows a basic configuration of the signal processing IC 201. Referring to FIG. 8, the signal processing IC 201 includes a playback amplifier 211, a recording driver 212 and a register circuit 213 built therein. The playback amplifier 211 is connected to a playback head such as, for example, an MR head 204A through the head wiring line junction section 207 by two signal lines 214 and 215, while the recording driver 212 is connected to a recording head such as, for example, a TF head 204B through the head wiring line junction section 207 by two signal lines 216 and 217.
A serial enable signal SENA, a serial clock signal SCLK and a serial data signal SDATA are inputted to the register circuit 213. The register circuit 213 controls a bias current to the MR head section 204A, a recording current to the TF head 204B and so forth based on information given thereto with the serial data signal SDATA.
In recent years, the storage capacity of the HDD apparatus has increased suddenly, and also the data rate has increased in proportion to the increase of the storage capacity. Since a rise of the data rate raises the frequency band, an improvement of the S/N ratio is required inevitably.
However, while in the head apparatus for a HDD apparatus, normally a playback signal of several mv is transmitted from the MR head 204A to the signal processing IC 201, since the transmission line from the MR head 204A to the signal processing IC 201 extends very long as can be seen from the foregoing description, the playback signal is liable to be influenced by disturbing noise. This causes a factor of deterioration of the S/N ratio.
Meanwhile, in the recording system, the sum of the inductance of the TF head 204B and the inductance of the board on the transmission line serves as a load to the recording driver 212. Thus, if the length of the transmission line from the signal processing IC 201 to the TF head 204B is long, since the load to the recording driver 212 increases in accordance with the length of the transmission line, when the data rate rises as the storage capacity increases, the recording speed cannot follow up the data rate.
It is an object of the present invention to provide a head apparatus, which is tough against disturbing noise and superior in the S/N ratio, and which can cope with an increase of the capacity of a recording medium and a hard disk apparatus and a recording and playback apparatus, which employ the head apparatus.
In order to attain the object described above, according to an aspect of the present invention, there is provided a head apparatus comprising a support section for supporting a head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
According to another aspect of the present invention, there is provided a hard disk apparatus, comprising a hard disk, and a head apparatus including a head section for recording and playing back information onto and from the hard disk, the head apparatus further including a support section for supporting the head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
According to a further aspect of the present invention, there is provided a recording and playback apparatus, comprising a head apparatus including a head section for recording and playing back information onto and from a recording medium, the head apparatus further including a support section for supporting the head section, a playback amplifier mounted on the support section for amplifying a playback signal outputted from the head section, a circuit section mounted on the support section for setting a bias current for the head section, a signal processing system provided outside the support section, and a transmission line for transmitting read data outputted from the playback amplifier to the signal processing system and transmitting serial data from the signal processing system to the circuit section.
In the head apparatus, hard disk apparatus and recording and playback apparatus, since the playback amplifier and the circuit section are mounted together with the head section on the support section for the head section, a feeble playback signal outputted from the head section is amplified by the playback amplifier once and then transmitted to the signal processing system by the transmission line. This increases the relative level difference between the signal level of the playback signal being transmitted and the noise level of disturbing noise. As a result, the playback signal becomes tough against disturbing noise and the S/N ratio of the playback signal can be improved.